221312124 has 36 divisors (see below), whose sum is σ = 610286040. Its totient is φ = 67064160.

The previous prime is 221312081. The next prime is 221312149. The reversal of 221312124 is 421213122.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 221312097 and 221312106.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 279039 + ... + 279830.

It is an arithmetic number, because the mean of its divisors is an integer number (16952390).

Almost surely, 2^221312124 is an apocalyptic number.

It is an amenable number.

221312124 is an abundant number, since it is smaller than the sum of its proper divisors (388973916).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221312124 is a wasteful number, since it uses less digits than its factorization.

221312124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 558890 (or 558885 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 221312124 is about 14876.5629094895. The cubic root of 221312124 is about 604.8788537797.

Adding to 221312124 its reverse (421213122), we get a palindrome (642525246).

The spelling of 221312124 in words is "two hundred twenty-one million, three hundred twelve thousand, one hundred twenty-four".